Polymers at an interface; a simplified view

An elementary description of polymers adsorbed, or terminally attached, at an interface is given. Discussion is restricted to linear, flexible, neutral chains in good solvents. Terminally attached systems, in the “brush” regime, have weak fluctuations and are thus amenable to a simple mean field description. On the other hand, the adsorbed, diffuse layers have large fluctuations and cannot be described in mean field terms. Adsorbed layers have a certain self-similar structure which allows for a compact interpretation of most fundamental data (ellipsometry, hydrodynamic thickness). Self-similarity has been proven most explicitly by recent neutron experiments of Auvray and Cotton which were made on long chains with variable contrast techniques. Recent advances on the kinetics of exchange between adsorbed and free polymer are also briefly described.